Fabrication of Low Cost NASA Personal Air Vehicle Concept

[saildapper2001]

As a private pilot, I've often thought I have a lot of manual 'options' (carb heat, magnetos, etc.) that made sense a long time ago, but even when future hardware is perfected and simplified with computer assistance, the training aspects of flying will continue to be a hurdle to mass popularization.

[NASAPAV]

There is really no reason for this. Read a few of our research papers on the Haptic Control System - which is a complementation system that takes advantage of humans for what they do (perception of objects, strategy and intent) and human automation (actually controlling vehicle). The analogy is developing a horse and rider experience - do you really want to have to tell the horse every single place and time to place a hoof, or you just want to nudge him which way to go...

[TedRobotBuilder]

Would the FAA really let you use a car engine? Everything I have heard says no. The motor has to redundant spark system that few car engines have.

[NASAPAV]

Yes, it is possible, many engines have redundant igniters and spark plugs per cylinder these days. Toyota fully certified the FV4000 Lexus engine for aircraft use - but they did alter the engine significantly because they were hooking it up to a propeller (which I think is crazy). An auto engine needs/wants to be a direct drive solution to a ducted propeller to work well for many reasons.

[TedRobotBuilder]

@NASAPAV, the LS1 in your video doesn't have duel plugs.

[TedRobotBuilder]

@NASAPAV, it would be nice if the FAA started thinking forward like that but they don't. Their heads are in the stone-age. I will eat a bag of dirt with a spoon if they let you use an unmodified LS1 in a airplane.

[NASAPAV]

Great bet - you're on! But we not pursuing this specific concept any longer. Take look at the Hyper Efficiency Concept that I also have posted. Would you make the same bet that we can't use a aluminum 4 cylinder straight from an auto production line? But to be fair you should understand that our strategy with that vehicle has matured - that is a redundant hybrid-electric powertrain, so the auto engine is just the cruise engine, and the electric portion permits redundancy

[NASAPAV]

Correct, but the LS-1 spark system is even better than want it is certified on aircraft today. This is what we were pushing - safety intent with adv techs, vs compliance that results in lower safety. The LS-1 uses an 8 coil system, with each coil a redundant, self contained ignition system, so there is redundancy. Sure you could lose 1 plug or 1 coil, but the engine is still going to put out plenty of power. Surely you can see the potential improvement...

[NASAPAV]

BTW, if you are interested in reading more about this, here is a website that discusses the LS-1 ignition system (just search Megasquirt LS-1 ignition system)

[AuroraCypher]

This is such a great idea and genius... but as soon as people thought of the license, the insurance, and parking space... safety and regulations....all these headaches the FAA could think of will stop any man from owning a personal airplane.

[NASAPAV]

Actually the FAA was quite cooperative in our studies of this concept feasibility, especially the certification of an auto-based engine. Many in the FAA want this type of vision to be successful, but their job is to ensure safety, above all else. So this creates a conflict - how much safety do you pursue? The same as airlines? Right now small aircraft are only 10^-4 reliable, not 10^-9 reliable like airlines, trying to push 10^-9 reliability unto small aircraft is unrealsitic.

[NASAPAV]

So the key is to help the FAA understand that if we can achieve 10^-6 levels of safety - it's still much better than if we they push on regulations that would achieve airline-like safety, that no one can afford. There are lots of mainstream technologies that are affordable, that can make small aircraft safer than they currently are - and the FAA needs to support efforts to get these technologies certified - even if they aren't up to airline standards.

[steelmesh]

LSx engines don't go 50,000 RPMs needed to move enough air for that turbine. I didn't see a gearbox, looked like direct drive.

[NASAPAV]

Yes, a small turbine will turn at 50K rpm - but this is not a small turbine, this is a 3.5 ft diameter ducted propeller which was designed to operate at ~600 ft/sec tip speeds with a direct drive from a derated LS-1 engine that can put out 300 hp. It is perfectly sized, in fact we built it and tested it with an LS-1 engine - worked perfectly, and very quiet.

[steelmesh]

@NASAPAV Pretty wicked!!

[NASAPAV]

If you want to see the full scale propulsion demonstrator, look at these videos on youtube user MunroAssoc videos this is the company in Detroit that fabricated our design for us.

[powwow151]

this might also be a good idea for a kit built type plane/ plans too. the builder would be using familiar parts

[NASAPAV]

Not really. This manufacturing concept focuses on a skin-stiffened structure with a small parts count and low touch labor - but this is done with some automated tooling. So much of the labor cost is removed, it would probably be just as expensive to buy as a kit, as to buy as a completely assembled vehicle. The net result is a 4 place, 300 hp aircraft that can be sold with a profit for $100K (instead of $400K for a Cirrus SR-22 with similar capability).

[powwow151]

what is that on the nose, a generator/ ram air inlet?

also, you don't have to just take it off of a car, just use the common parts new from the auto factory in the assembly.

[NASAPAV]

It's the radiator for the engine (the LS-1 corvette engine is liquid cooled). Using auto-based parts is the core of the idea - taking them off the car is just for visual representation.

[64wing]

looks like they have no consideration for weight savings...or weight and balance for that matter...all of those components weigh significantly more than items of the same purpose that are actually used on aircraft...

[NASAPAV]

The objective was not to achieve the lightest weight, but the best compromise between cost and performance. Yes, the aircraft balances. The weight is a bit higher than existing baseline aircraft concepts - but the cost differential is huge.

[64wing]

@NASAPAV you can get in the air for as little as $15,000. The man hours that would go into transferring car parts to an airframe wouldn't be worth it. I'd rather build from scratch. I'm not saying the thing wouldn't fly...but I wouldn't want one. Take it from a marketing guy (pilot also), the people that would be interested in this design are the same people that think their piloting skills are determined by their wallet depth...and I don't want them in the sky with me!!

[NASAPAV]

This is typical pilot perspective. I understand it, but disagree - you need to open your mind to other possibilities, and make fair comparative statements. Show a new 4 place, 300 hp aircraft capable of 160 knots and 500 mile range. Trust us that we have put more effort into this study than merely off the cuff statements made without even reading our research reports. Sure build from scratch and let's talk 2000 hours later - the key to GA staying alive is to get away from this

[64wing]

@NASAPAV with all due respect to your research, I disagree. The way to keep GA alive is to provide reasonably affordable aircraft (be they used or new, kits or production models). I have spent my whole life in aviation, so please do not insult me by insinuating that I have not researched the issue. I have. As for your challenge. How about a Vans RV-10. Four seats, better than 160kts off of less than 300hp, 720nm range. A builder with good help could do it in 1400 hours. Food for thought

[64wing]

@NASAPAV with all due respect for your research, I disagree. I have spent my life in aviation, so please don't insinuate that I have not been carefully observing and considering new developments. As for your request: the Vans RV-10 is a four place, better than 170kts off of less than 300hp, and better than 710nm range. A half-way decent builder could put one together in 1400 hours or so. AND it's from a kit. The key to keeping GA alive...is being realistic, like the folks at Vans

[64wing]

@64wing also...this is a real question. Not trying to be overly critical of the design at all, just curious. How does rudder and elevator effectiveness fair with the lack of the traditional slipstream??

[64wing]

@64wing those numbers are at gross weight too

[NASAPAV]

The LS-1 engine worked flawlessly in the full scale demonstrator of the aft section of the aircraft. It permitted a direct drive solution at 4000 rpm with 300 hp for less than $10K. It passed the FAA Part 33 endurance test without any issues - so why forget it?

[Aeromakerable]

@NASAPAV

I have over 200 actual flight hours using the LS series engine. They are definitely superior to the current air cooled engines. Cooling with cowling poses some problem along with adequate PSRU's . The direct very long drive shaft in this PAV may pose some problems, but not insurmountable. There are a lot of fine tuning points, but overall this concept can be accomplished.

Where or whom might I address for more detailed info?

[Aeromakerable]

@NASAPAV Where is the coolant system? I suppose in front, but I saw no radiator. Plenty of room there and will help CG.

[whatever7x7]

@Aeromakerable @0:49 the first item to be pulled from the cart is the radiator.

[NASAPAV]

It is up front and shown in the video. There is a small circular opening at the front nose with a radiator right behind it, and an annular exhaust that provides warm external air on the windshield to provide external defogging.

[58Vulcan]

@NASAPAV Can we have a few pictures of the real thing or did they spend all the budget making this video?this is two years old what progress has been made?

What is the planned take off and landing speeds-is it going to take off from normal roads.

An LS1 in aircraft is old hat anyway

[NASAPAV]

There are videos of the full-scale rear portion of the vehicle (the entire propulsion system) from the company that worked with us (Munro & Associates in Detroit). I have conference papers that discuss the concept, and pictures of the unit.  TO and landing speeds are equivalent to existing 4 place GA aircraft - no, the aircraft is designed to take off from small airports, not streets. The LS-1 was the best available engine at the time of design.

[0nem1leh1gh]

Looks cool, but forget about the car parts. Take Lycoming, Continental, or consider a fuel cell/battery hybrid, but forget the Corvette engine nonsense.

[NASAPAV]

Wrong - read the technical paper about this concept and you'll understand better. Do you realize the cost differential between an LS-1 based propulsion system vs a 300 hp Lycoming. It's a factor of 5 difference in cost. Fuel cells - ridiculous costs and will be for a long time. This study was to prove that a $100,000 4 place aircraft of similar performance could be developed - at 1/4 the cost of competing products.

[0nem1leh1gh]

@NASAPAV Ah yes, the numbers. Well, i don't trust carparts in an aircraft. Ask Thielert, who transfered a Mercedes diesel into an GA aircraft. What seems to be a good idea first, turned out to be high risk technology, which caused aircraft to crash, including loss of lifes.

[cpnstav]

Why not appreciate what NASAPAV is trying to "Convey"" instead of knocking it. A brialliant video and a great idea

[Tjita1]

I have to ask why on earth you would use car seats in an airplane, they weigh tons!

[NASAPAV]

You wouldn't, that was just the animator visually expanding on the idea that as much part commonality would be used between autos and aircraft (especially if they are not flight critical and don't involve liability concerns). But aircraft seats have unique safety requirements that are quite different from auto seats.

[dunners2004]

The biggest design problem for personal air vehicles is producing high lift at low speeds so that a short takeoff and landing run can be acheived. Rotary aircraft are very good at VTOL but their complxity let them down for the general user and their straight line performance is generally poor. In order to acheive this high lift at low speeds either tilt fans are needed to vector thrust downwards, or an adaption of the Custer channels (Or spiral ducts) could be used. Nice animation though!

[NASAPAV]

Not the same thing. This vehicle is about achieving a low cost Conventional Takeoff and Landing aircraft - not STOL or VTOL which is a completely different mission, which is much harder and much more expensive. High lift is simply not an important issue for CTOL aircraft that are taking off in a 2500 ft runway due to the stall speed limitations for Part 23 aircraft.

[StarJar58]

Dude, I'm a pilot, and although this is interesting I know you are not NASA. Nothing wrong with toying with ideas though.I like the tail groups supporting the duct, that's cool. Before throwing driveshafts in, you have to realize the headaches others have run into getting the vibration out. The seats in cars are quite heavier than aircaft ones.Nice animation. Anyway, I'm a dreamer and designer like you. Best wishes.

[inagod]

the only way I see it,is using stamped steel or aluminum panels,carbon fiber is just too expensive.

[NASAPAV]

That is precisely the idea - stamped aluminum panels with very little touch labor with a skin stiffened structural concept.

[LimbagoAeronautics1]

It would be crappy if planes of today will be replaced with the automated flying cars of tomorrow,I mean,where's the excitement?Where's the fun?Where's the thrill of flying will be?Blown away by the wind?

[polzowatel]

thats not enough power 

[NASAPAV]

300 hp is not enough power (the LS-1 is up to 400 hp but we derate it for longer life and to match up to the ducted prop rpm without a gear reduction).

[NASAPAV]

My point was, yes, 300 hp is plenty of power to meet the mission requirements.

[soulblazer91]

@Dolphin8097 Whenever mass personal aerial vehicles come about, there will be close to no manual operation of these things. Boeing and other major companies have already addressed this with very sophisticated programs (auto pilot) that will communicate with other vehicles as to their destination and will recalculate their fight paths so that everyone gets to their destination without problems. It also allows for the creation of restricted areas where people can't fly. Your fears are addressed :D

[Dolphin8097]

Looks like a hazard unless the same requirements apply to get a license to fly this as a small prop aircraft. If you have too many every-day people flying around above our homes and they are the same fools I see driving on the street, I believe that I have a legitimate reason for concern.

[Whitehorze]

Cute, but i'm sticking with a composite structure and a diesel engine. Your wingspan and control surfaces are out of proportion, and using automotive components is not weight efficient. I'd have to see a dynamic flow sim to see how the structure performs in cross winds and uneven loadings.

[NASAPAV]

Then you are sticking with a $400,000 cost for a high performance 4 place aircraft. The intent of this design was to achieve a 4x reduction in cost, while only taking slight performance penalties, and achieving many additional design benefits that are not typical considered (such as drastically reduced community noise). The wing span is appropriate, the wing control surfaces are not shown, the tail surfaces are properly sized (given the desire to use the same tooling for Vert and Hor).

[Whitehorze]

@NASAPAV Composite doesn't mean carbon fiber.

[NASAPAV]

No, but composite means lots of touch labor. Cirrus requires over 2000 hrs of man hours to put together their aircraft - changing to fiberglass isn't going to reduce the labor required, just the material cost. We looked at where the cost is, and the problem is in the labor hours required for these low production volume vehicles. I agree with composites when only 500 aircraft are going to be built per year - but such markets are merely niches, and not what we were addressing.

[NASAPAV]

Composites mean lots of touch labor

[NASAPAV]

Concerning weight, yes, there is a weight penalty for both the auto engine and duct. But by using such, the engine cost is reduced by a factor of 8x (while still be certifiable) and a direct drive to the fan eliminates any need for gearbox, and provides a far lower vibration (NVH). So sure, stick with a noisy, rattling diesel - and if it happens to be a Thielert - opps, that's an auto derived engine as well (from Mercedes).

[Whitehorze]

@NASAPAV I understand your skepticism, but since your focus is on the price/performance equation.

dieselenginetrader@com/index.c­fm

eaa@org/news/2008/2008-04-12_i­ndus.asp

ppdgemini@com

[NASAPAV]

What is your point? Indus is attempting to use a skin stiffened structure, just as we have proposed (but they didn't design for volume production, so couldn't get the cost benefit). There is no way any engine can compete with the quality or cost of high volume auto engines - the key question is, how can you use an auto engine on an aircraft without destroying it (ie attaching a gearbox and having the impulsive loads of the piston and prop tearing each other apart - especially with a diesel).

[NASAPAV]

Send me your email and I will email you a paper that describes this concept in detail - and the specific trade-offs that were made to accomplish the design objectives.

[marmaladekamikaze]

@NASAPAV

I am very grateful that you have provided these videos, I am wondering if you, or your team, have done any work on Wing in ground effect aircraft? as I have read they are very fuel efficient.

Thank you again!

[NASAPAV]

No, but I have many papers on WIGs, and have looked into them. I don't see enough of a payoff, considering the penalties. Yes, flying at 5-10% height above the water will yield about a 50% reduction in induced drag (so 1/4 of your total drag). But remaining at zero altitude means high parasite drag, and maintaining close proximity to the ground is the unsafest way to fly - there is simply no reaction time due to the close proximity of the water if something happens. But WIGs are cool.

[marmaladekamikaze]

@NASAPAV

Always interested to hear experts opinion's on concepts, I'm particularly fascinated by WIGs because of their good fuel economy and capability to land on rivers, opening up access to most cities in the world. I hear your criticisms and I take them on board, perhaps something akin to Terrain Contour Mapping would assist in reducing the likelihood of a crash? Longer wings may also be employed, Do you know of any other aviation vehicle that could match WIG's low running costs?

[NASAPAV]

While you are correct that it would be difficult to match the low induced drag of a WIG - this does not mean they have low operating costs. The Soviets had operational experience with the Kaspian Sea Monster, and that was certainly not low cost. Operating in a salt water environment is toxic to an aircraft in terms of maintenance cost. The key question is what mission or objective are you really trying to satisfy - instead of trying to justify working on WIGs, and let the best vehicle fit.

[marmaladekamikaze]

@NASAPAV

I am curious to hear your opinion on this aircraft,

watch?v=Az7E1OTZnZc

It's titled ''Tilt Rotor Coaxial Helicopter VTOL RC'' if you wish to search for it yourself.

[Photonzos]

meanwhile airships come back into fashion

[zebadee277]

im sure theres a lighter less fuel hungry engine you could use than 1 from a corvette lol

[NASAPAV]

This was done 8 years ago, and the Corvette engine was the best 350 hp engine around, including fuel consumption and being lightweight. In addition, the Corvette engine was a Low Emission Vehicle engine, with extremely clean combustion. Overall, the LS-1 engine was an extremely impressive engine that could withstand the aircraft duty cycle being it was so robust. So no, no better engine was available at that time.

[zebadee277]

@NASAPAV are you talking US made engine? as in EU, 350 hp is kinda lame for a v8 even back in 2002

[NASAPAV]

It's the power at rpm that matters, 350 hp at 4000 rpm, which is what the 3.5 ft diameter duct required. Show me a better engine (sfc, weight, emissions, durability) - even today I doubt their are many that could compete with the follow-on to the LS-2. We looked at the Toyota Lexus engine in depth, as we had data from the FAA on that engine being certified - way too complex of an engine. We tested the LS-1 in a full 300 hr FAA Part 33 endurance test, and the LS-1 was bulletproof solid.

[beedylove]

amazing, but it has no ailerons

[davidls11]

Why not just wait four years and get one of those Back to the Future hover conversions?

[tiltrotorcoaxialheli]

check my channel for a flight test videos of semi scale Tilt Wing PAV

[2solerio]

how much would one run?...and what license would u need to fly one?

[silentbob151]

waste of a perfectly good corvette



[DigitalSocietyOrg]

Are those ribbed indentations in the wing and stabilizer for extra strength? That's my guess since there's nothing holding the shape of that metal skin in between the ribs.

Are the wings made of stamped aluminum? What's the spar and rib material, also aluminum?

[NASAPAV]

Yes, it's called a 'skin stiffened' structure - and the reason why so few ribs can be used, and without stringers. The intent is to radically reduce production labor required, and thus the cost. Skin stiffened structures have been used on aircraft previously (the Republic Seabee), on automobiles (look at the Chrysler hoods), etc.

[01248163264128256512]

@NASAPAV And, most notoriously, extensively used on Soviet equipment such as trains and military vehicles, and specially on earlier Junkers airplanes, such as Ju-52 model.

[NASAPAV]

Yes, it's called a 'skin stiffened' structure - and the reason why so few ribs can be used, and without stringers. The intent is to radically reduce production labor required, and thus the cost. Skin stiffened structures have been used on aircraft previously (the Republic Seabee), on automobiles (look at the Chrysler hoods), etc.

The structure is all aluminum

[DigitalSocietyOrg]

@NASAPAV Is the skin aluminum too?

How is it bolted on to the ribs, metal rivets? I'm assuming you don't want any rivets towards the front of the airfoil?

[NASAPAV]

Rivets connect the ribs to the aluminum skins, by use of an automatic riveting machine (again, as used in the Republic Seabee). Literately the spars, skins and stamped skins are placed in a jib and then all at once with a large press machine, the drilling/rivets are placed all at once with almost zero touch labor (but increased tooling cost). This vehicle is designed for production volumes of at least 2000 units per year - and an outside costing study showed 1/3 cost of current airframes

[NASAPAV]

The rivets go all the way to the leading edge. With a ribbed (skin stiffened) structure, you will not see laminar flow - so the wing is designed to be fully turbulent, so it makes no difference having the rivets go to the leading edge. A very interesting experimental study showed that a ribbed structure was able to achieve an equal drag as non ribbed structure, because it was able to insure no separation do to the 3D flow effects of the rib. Of course a composite, laminar wing is less drag.

[geekfish]

Crap.....!!! How many rpm would the fan need to spin at?

[NASAPAV]

3500 to 4000 rpm - which is peak torque for the LS-1 Corvette engine that we tested. A full scale engine and propulsor was tested to demonstrate the low noise level goal which this design was seeking. The LS-1 was also tested through a FAA Part 33 endurance test to showcase how an auto engine could meet certification requirements, through the elimination of any gearbox and the low impulsive characteristics of a ducted propeller vs a conventional propeller

[geekfish]

@NASAPAV So at that rpm the blades are able to create enough thrust...? I take back my trollie' statement...:) Wait a sec? The engine will be at 3500rpm but what will the rpm of the blades be? I am guessing they would need to turn in the 10's of thousands, is this correct? If so, not seeing a vet tranny creating that? What is the blade rpm you calculated?

[NASAPAV]

The whole point of using an auto engine in combination with a ducted prop is to avoid requiring any gearbox - so the engine and ducted propeller are both turning at a peak value of 4000 rpm (which is the peak torque output for the LS-1 engine). The max rpm of the LS-1 is about 6000 rpm, so we are derating the engine for longer life by only using the engine up to 4000 rpm. At cruise the rpm is more like 3500 rpm. This permits the tip speed of the prop to be about 600 ft/sec for low noise.

[geekfish]

@NASAPAV

Cool, hope it gets built.....

[datzfast]

man i love that self assembly concept i mean think about it you throw in some magnets in just the right spots and the thing floats together under water. those guys at NASA are just so smart. i bet they got the idea when they were doing all those self assembly things with electromagnets in the weightlessness of space. NOT

[platinumplusenter]

Very inspiring video.

[sweetlikeADAM]

Lol, that tiny fan on the rear wing is going to propel that plane? And it would definitely need a higher performance engine.

[IlersichProductions]

@sweetlikeADAM I think NASA knows a little bit more about aerodynamics than Youtube commenters.

[sweetlikeADAM]

@IlersichProductions It's called a concept for a reason...

[IlersichProductions]

@sweetlikeADAM ...that reason being that it is a feasible idea.

[ElevenDancingRhino]

all of the cheapest parts are recycled

[h3xyournightmare]

the engine it's too heavy...and the concept looks more like a torpedo plane ;)

[Ecurrie84]

NASAPAV,

surly with electric engine powered VTOL stle crafts are better than this,

how come no "SMART MATERIALS" like morphing metals are being used for shapes of these crafts you are designing.

Think about it, electric power, VTOL capabilities and morphing metal you have at your disposal and you are coming up with this thing,

it seem's NASA are not allowed to get too high tech, it seem's NASA is controlled by someone other than who they claim.

[NASAPAV]

This was a concept from an effort 7 years ago that I led - the intent was not to push technologies (like the electric VTOL), but instead prove that aircraft could be built for 1/4 of the current cost. But to do so required approaching the design very differently than small aircraft companies do so (even today). So you are correct, this aircraft was not about tech, but low cost (and low noise). But it still pushed hard on the assumptions that currently exist for small aircraft.

[Ecurrie84]

Seen's you put it that way then this is indeed a great idea,

I can see you take the right approach towards designing aircrafts,

cheap safe air vehicles for all the people not just the rich with millions,

good on you.

[sugercoatedvenom]

its better to develop more eco-friendly technology for existing vehicles like cars, and planes. the average human does not have a place to store this type of PAV

[NASAPAV]

As long as you are happy to drive an hour to a hub airport, arrive an hour early to get through security (undress), and wait around for baggage, and then finally drive an hour to where you really want to go (which isn't close to that hub airport). All this to go a on a 300 mile trip (and don't forget the ground congestion). This provides a fractional/rental solution for low cost personal aviation, which could be much faster and effective with mid range travel.

[jewlzorjay]

@NASAPAV Does it work? could i build one today and have it work? if people could easy build there own aircraft than surely technological development will be pushed hard and a eco-friendly solution will be found sooner. You might get auto-mobile companies getting in on it.

[NASAPAV]

An auto company worked with us on this project, and performed the cost estimates (because they had access to the proprietary costing data that we would never have). Yes, this could be built today, including the ease of use flight system so that anyone could fly it - and the result would be $100K aircraft that could serve as air-taxis and air rental planes. But the key to this concept meeting that price and making sense, is that the production volume must be at about 5000 units per year.

[jewlzorjay]

@NASAPAV so commercially its a good money saver for a small island that is too small for jumbo's and has a developing economy. somebody like Richard Branson could potentially buy a small fleet of these to get people to and from his island. that could account for a small number of units and i suppose the rest would have to come from the type of person who already has a plane. But i think for this to bought on a huge scale the price would need to go between £25,000 and $50,000

[NASAPAV]

I agree - the key is getting the cost lower for entry - which is why focus shifted to the ultra efficiency concept (which still utilizes much of the same manufacturing cost reduction). But that other concept let's us get the number of components even lower, and the size of the motor down by more than half (although it becomes a ~140 mph aircraft instead of 175). I think the Hyper concept could get down to $50K but we didn't do a cost study (it also has other limitations such as CG excursion).

[Croopskate]

@sugercoatedvenom

you're referring to short-term cheap solutions. R&D is never cheap, but can lead to great savings in the long run. think about mass production...

[kibcubed]

I don't think such projects for NASA aren't mere frivolities. People like the thought of space travel in the same way people like motor-racing. It pushes the envelope of what our technology can achieve, and gives us a sense of pride. But technical trickle-down is slow from such endevours. At least NASA tries to directly address concerns of ordinary people on the ground rather than pursue an ideologically fueled space race.

[NASAPAV]

Wow - I like this guy, exactly my thoughts. Less than 1/40 of NASA's budget goes into Aeronautics. In fact, NASA spends $150 million just on education, and only 3x that on Aeronautics. But Aeronautics research has the potential to improve our daily life, expand our productivity and economy - so my vote is for more Aeronautics research that can make the world we live in better, more environmentally friendly, and more accessible.

[kibcubed]

I like the design, and understand a ducted fan can operate at a car engine's RPM range. I even like the possibility of vectored thrust. But such a long drive shaft strikes me as really awkward and heavy, and I also imagine prone to imbalance in the long run. Can't the shaft be eliminated and the fan placed in front of the tail, with a boom extending underneath it to accommodate the rear control surfaces?

[NASAPAV]

Ah you mean a Strojnik type of design. Yes, you could do that, however, close coupling the ducted prop to the body will be very problematic. This was tried with the Cessna 327 in our Langley wind tunnel - terrible inflow, quite noisy, and poor propeller efficiency. Close coupling the prop is just not a good idea. But I do like Strojnik's designs - and they make a lot of sense, if you can get the prop to behave well.

[kibcubed]

Thank you for your prompt reply. I Googled the design, and see what you mean. I suspected the fuselage would wreck airflow into the fan, but thought I'd mention the idea anyway. I suppose if a short shaft was used so that the rear of the fuselage would taper into the fan it wouldn't so closely coupled, and maybe vortex generators on the sides to enhance flow into the fan. Its a trade-off, though. You still have a shaft, and then you loose rear seat room from the tapering. Just my two cents.

[NASAPAV]

I agree that they should be compared and contrasted. The long shaft is non-ideal. But if you look up the Munro Paradigm on Youtbue (which was our full scale demo of the back end of this aircraft) the shaft was not a major problem - just extra weight. My ideal preference would be to closely couple the fan with a boundary layer ingestion system - such as the Goldschmied propulsor - you can see an example of that with my Hyper Efficiency concept on Youtube. Thanks for your input,.

[kibcubed]

And thank you for entertaining my questions, sir/ma'am. I suppose if a P-39 Aircobra can use a shaft despite the stresses it would encounter, this shouldn't be a problem. I do like the engine smack-dab in what I'm guessing is the concept's CoG, and again the potential for vectored thrust. Again, thank you and you're welcome.

[mrmaciejm]

that's where nasa wastes money...

[6LuckyGillz]

cooooolllll

[yumyumsashimi]

I think it can be done for under $250.000 but you would have to scrape useing the heavy chevy engine and seats etc. RR has a new powerful lightweight turbine that is allready faa cert. or a rotory engine would be light and reliable.

[NASAPAV]

I'm sorry, you are going exactly in the wrong direction. Sure, swap an incrediblely inexpensive all alum auto engine for a $100-$200K turbine. We did very detailed cost trades, the weight saving s the turbine is trivial in terms of cost savings in aircraft weight growth. Sorry, do the numbers.

[welshpete12]

the engine is going to come foreward in a crash into the crew compartment !

[NASAPAV]

Good thinking, but not quite - we also saw that. Many prior rear engine vehicles (cars and planes) will use mounts that cause a break away rotation under sudden deceleration (ie top mounts weaker than bottom). This lets the engine flip up or down, instead of acting as a hammer (with you as the nail).

So this issue has been addressed in many prior designs.

[mowgli2071]

Watching the assembly, even if I didn't love planes, is hypnotic. Also reminds me of legos, somehow.

[eqtworld]

Aircraft are not expensive because they are costly to make, they're expensive because of liability.

You could build a Cessna minus engine for 5k in parts. The engine is 60 year old tech but costs a fortune to rebuild because of the liability.

The reason a new Cessna is 300k has nothing to do with materials cost; it's that price because people like to sue.

Taking the engine out of a $60,000 car ain't going to make it cheaper. The aircraft in the video could never be sold for under a 250k.

[NASAPAV]

You are not correct, but have some good points. Look at the Cirrus SR22 (a new aircraft) - about 2000 hours of assembly labor - that's about $100K just to put it together. The engine is over $30K, the avionics, etc... The liability reserve is less than 25% of the vehicle ($100K). Aircraft companies are in a catch 22 of high costs and need a paradigm shift to break out of it. Being able to use COTS is possible, the FAA was a partner in this study.

[eqtworld]

@NASAPAV

The fact that even to be pedantic and go out to find the one new aircraft bought out by that company; the Cirrus is a decade old design. This proves my point, not yours.

[NASAPAV]

The LS-1 can be bought crate complex for $6K, and passed the FAR Part 33 test. The key is to design the aircraft from the start for low assembly time, COTS parts, with an integrated lean design approach - instead of designing them simply as an engineer that loves aircraft. Even without liability if cars were designed and built the way small aircraft are - they would cost just as much as aircraft. Liability is an excuse more than anything else.

[eqtworld]

@NASAPAV

Liability is not an excuse. Look at what happened to nearly every maker of small aircraft 40 years ago- they were sued out of existence.

You can put together an "experimental" 0-235 for 6k, if you want the exact same engine yellow tagged and certified it's 25k. Construction or parts cost is nothing compared to having the parts certified.

How much do you think this plane will cost? IMO there is no possibility to realistically produce it for under $250,000

[NASAPAV]

Liability is an excuse - other transportation devices have overcome the liability hurdle. Liability is a real hurdle - but it is not the defining situration you infer. Just as certification is a barrier, but not a complete obstacle to innovation. The ASTM LSA standards are a step in the right direction - however, LSAs are still way too expensive - not becuase of libability, but because of low production volume. The new Cessna Skycatcher is $111,000. If 10K instead of 500 - cost would be 1/2

[eqtworld]

@NASAPAV

That is true but the impediments to getting a pilot's license (they are stringent to decrease liability by requiring thousands of dollars of training and months of studying just to get a license.)

There are several new aircraft you can buy in the 50k range; but none of them are 400hp.

There is a company, American Legend, that remakes, the J-3 cub (the most simple construction ever, tube/fabric/small motor/100mph cruise) and a new one is over a hundred thousand dollars

[AG51LZ]

My tax dollars are being used to make designs to compete with Cessna & Piper? It's not even a good design. Good luck getting a Chevy V8 lump FAA certified. Please tell me this is a joke.

[NASAPAV]

Not to compete with them - to help them. This efffort specifically developed a quiet ductt that could be direct driven by any auto engine. Another part of the effort worked with the FAA to do a Part 33 engine test on an LS-1 engine, and show a detailed cert path that US small aircraft manufacturers could use. So our intent was to help them get past their 40 year old designs, use COTS engines, and achieve low noise. I guess these are bad things in your mind?

[eqtworld]

@NASAPAV

They can't/don't design new aircraft because of the cost to get the FAA to certify a new aircraft design.

It's all fun and games till joe idiot flys this thing into a mountain, his family blames the visibility and sues you... look at what is REALLY going on in aviation

An alternator with STC can cost $500 even though it is EXACTLY the same design as a $79 car alternator. The cost is in the liability of letting someone use it in a plane; not the parts.

[ineedpaintball]

i like how everything magically flies into place, yet the glass is attached by robots

[Mickorec]

@ineedpaintball

Lol I din't even catch that. Kinda the same way they unload a gun on Superman. He just stand there have the bullets bounce off his chest like popcorn. But when the bad guy throw the gun at him--he duck for cover.

Professionalism.

[pistonturbine]

I get the point. Mass production will come to aviation when a low-cost, high power density generator is mass produced. This is definitely not science fiction. We need a new Moore's law for thermodynamic machines, doubling efficiency and power density every 18 months.

[DanFrederiksen]

other than using a car engine, how is this really low cost?

all planes could be made cheaply. they just aren't

[Nopp3]

well for one it seems to be suited for home fabrication,

and it seems to be made for short distance, low latitude flights so alot can be saved at that

seems to me like a bare bones consept, i doesn't even have airlions

[NASAPAV]

We have a full paper on this concept, if you would like to read it, just send me your email. It is much more than simply using an auto engine. The concept is all about achieve lean design, something practiced very well with auto companies, but not with small aircraft manufacturers. It is not focuesed to home production at all, but focused on using high volume production tooling in a way that can be used successfully, even at lower production volumes.

[Aeromakerable]

@NASAPAV where do I send my email. I assume this will get me a copy of this paper.

woodwardloyd@gmail.com

[maux999]

Nice x)

[zee1053]

cool.took a while though : )

[crash0510]

looks usefull